Staple fiber cutter



March 24, 1942. H. o. DAVIDSON I I STAPLE FIBER CUTTER F iled Sept. 25, 1941 I INVENTOR. HUE/ERTU. DAV/BEEN Patented Mar. 24, 1942 STAPLE FIBER CUTTER Hobart 0. Davidson, 'Swarthmore, Pa., assignor to American Viscose Corporation, Wilmington,

Del., a corporation of Delaware Application September 25, 1941, Serial No. 412,237

7 Claims. .(Cl; Hit-61) The invention relates to the cutting of staple fibers from bundles of continuous filaments and more particularly to that type of apparatus which involves the use of centrifugal force in drawing the bundle of filaments'to be cut into the path of a knife, such as is described in the Beria Patent 1,723,998,

In using this type of apparatus, a certain amount of twist always is associated with the filament bundle because of the rotation of the radially extending portion of the bundle about rotatable sleeve for rotation therewith. Supported in the bearings l3 and H of the support 8, there is a hollow shaft l 5 concentric with shaft 3 and provided with a pulley [6 by which itinay be driven independently of shaft 3. The upper end of the hollow shaft l 5 is provided with a gear the axis of the filament bundleas it is fed into the rotating discs The amount of twist depends upon the rapidity of feed of the bundle to the disc and speed of rotation'of the disc. Since this twisting occurs about the axisof the filament bundle, the lengths of the filaments surrounding the centralfilaments of the bundle are of increasing length as they occupy a greater distance from the center of. the bundle, such comparative lengths being taken over a given unitary length of the bundle. Since the twist is present-in the filament bundle at the position of cutting, the result is a non-uniformity in the lengths of fibers cut therefrom. It is an object of this invention to so modify the apparatus of this type as to provide an independent control over the amount of twist present in the filamentbundle as it emerges from the rotating disc into the cutting knife. This controlling means provides a way of obtaining either decreased or increased twist in the filament bundle as it emerges from the disc or it may be operated in such a manner as to substantially entirely remove the twist imparted to the bundle by virtue of the rotation of the disc about its axis and about the axis of the bundle as it is fed to the disc. I In the drawing, illustrative of the invention, Figure 1 is a plan view of the modified device, Figure 2 is a front elevation of the device, partially in cross-section, and

Figure 3 is a front elevation of a modified" form of the invention.

ll whichmeshes withthe gear l2 for rotating the hollow sleeve 5 in the disc 2.

The extent of untwisting or additional twisting which may be imparted to the filament bundle by rotatable sleeve 5 depends upon the length of the sleeve, the frictional characteristics of the interior surface of the sleeve with respect to the filament bundle, and the speed of rotation and direction of rotation of the sleeve.

The twisting of the filament bundle about its axis as it enters the rotating disc results in an S-twist by virtue of the'counterclockwise rotation of the disc asviewed in Figure 1. In operation of the device in accordance with the invention, gear I! may be held stationary, thus increasing theS-twist by virtue of rotation of gear I2 on thesleeve about the stationary gear. By ro-' tating the gear l1 clock-wise as viewed from the top of Figure 1, the S-twist may be still further increased. On the other hand, by rotating the gear counterclockwise as viewed from above Figure 1, the S-twist may be decreased partially or 1 entirely or by further increasing the speed of rotation of this gearin this direction, the filament bundle may be given a Z-twist.

' In Figure '3, a modification .is shown in which untwisting of the tow as it passes through the In Figures 1 and z of the drawing, the disc 2 mounted on the shaft 3 for rotation is provided with the customary funnel-like opening 4 for re- "ceiving the bundle of filaments fed thereto, and

is provided with a sleeve 5 rotatable therein and having its inner bore 6 in register with the axially The. disc 2 is further provided with the opening II to Y accommodate the gear [2 which is secured to the disc 2. If desired, gear I 8 may be mounted for rotation, which event any desired extent of twisting or ,untwisting may be obtained. Thus, the device of this invention'affords a meanswhich may be controlled to obtain any desired diversity in the lengths of the fibers cut from-the filament'bundle as well as means whereby the twist may be entirely removed from the bundle to produce fibers having substantially uniform lengths.

While a'preferred embodiment of the invention has been disclosed, the description is intended to be illustrative only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the invention as defined by th appended claims.

What I claim is:

1. An apparatus of the character described comprising cutting means, centrifugal means for directing a bundle of filaments periodically to said cutting means, and means associated with said cutting means for controlling the twist imparted to'said filament bundle by said cutting means before the bundle, enters said cutting means.

2. An apparatus of the character described comprising cutting means, centrifugal means for directing a bundle of filaments periodically to said cutting means, and means for controlling the twist in said filament bundle as it approaches said cutting'means.

3. .An apparatus of the character. described comprising cutting means, centrifugal means for directing a bundle of filaments periodically to said cutting means, and means comprising a member rotatable about an axis extending radially within said centrifugal means for controlling the twist in said filament bundle as it approaches said cutting means.

4. An apparatus of the character described comprising cutting means, centrifugal means comprising a radial channel for directing a bundle of filaments periodically to said cutting means, a sleeve rotatable within said centrifugal means about its axis and having its bore disposed to constitute at least a portion of said radial channel, and means for rotating said sleeve with respect to said centrifugal means.

5. An apparatus of the character described comprising a rotatable disc, achannel therethrough having a generally axially extending portion and a radially extending portion, a cylindrical sleeve surrounding at least part of said radially extending portion, ,means for rotating said disc and means for rotating said sleeve about its axis.

6. An apparatus of the character described comprising a rotatable disc, a channel therethrough having a generally axially extending portion and a radially extending portion, a cylindrical sleeve surrounding at least part of said radially extending portion, cutting means adja cent the periphery of said disc, means for rotating said disc and means-for rotating said sleeve about its axis.

'7. An apparatus of the character described I comprising a rotatable disc, a channel therethrough having a generally axially extending portion and a radially extending portion, means for feeding a filamentary bundle into the firstmentioned portion oi said channel, a cylindrical sleeve surrounding at least part of said radially extended portion, cutting means adjacent the periphery of said disc, means for rotating said disc and means for rotating said sleeve about its axis at a speed sufiicient to remove from said bundle the twist acquired by virtue of the rotation of said disc.

HOBART O.- DAVIDSON. 

